The Question of Reincarnation
On that momentous night when the Buddha attained enlightenment, it is said that he went through several different stages of awakening.
In the first, with his mind “collected and purified, without blemish, free of defilements, grown soft, workable, fixed and immovable,” he turned his attention to the recollection of his previous lives. This is what he tells us of that experience:
I remembered many, many former existences I had passed through: one, two births, three, four, five … fifty, one hundred … a hundred thousand, in various world-periods. I knew everything about these various births: where they had taken place, what my name had been, which family I had been born into, and what I had done. I lived through again the good and bad fortune of each life and my death in each life, and came to life again and again. In this way I recalled innumerable previous existences with their exact characteristic features and circumstances. This knowledge I gained in the first watch of the night.
Since the dawn of history, reincarnation and a firm faith in life after death have occupied an essential place in nearly all the world’s religions.
Belief in “rebirth” existed amidst Christians in the early history of Christianity, and persisted in various forms well into the Middle Ages. A number of influential Christian theologians in the second century, particularly those who studied and taught in Alexandria in Egypt, are known to have believed in transmigration or the “pre-existence of souls”.
Although Christianity eventually rejected the belief in reincarnation, traces of it can be found throughout Renaissance thought, in the writings of major romantic poets such as Blake and Shelley, and even in so unlikely a figure as the novelist Balzac. (Other figures in the West in modern history who have apparently believed in rebirth have included: Goethe, Schiller, Swedenborg, Tolstoy, Gauguin, Mahler, Arthur Conan Doyle, David Lloyd George, Kipling, Sibelius, and General Patton.)
Since the advent of interest in Eastern religions that began at the end of the nineteenth century, a remarkable number of Westerners have come to accept the Hindu and Buddhist knowledge of rebirth.
One of them, the great American industrialist and philanthropist Henry Ford, wrote: I adopted the theory of reincarnation when I was twenty-six. Religion offered nothing to the point. Even work could not give me complete satisfaction. Work is futile if we cannot utilize the experience we collect in one life in the next. When I discovered reincarnation … time was no longer limited. I was no longer a slave to the hands of the clock.… I would like to communicate to others the calmness that the long view of life gives to us.
Source: Sogyal Rinpoche. The Tibetan Book of Living and Dying. 20th Anniversary Edition. Edited by Patrick Gaffney and Andrew Harvey. New York: HarperCollins, 1994.

I then like to ask people to ask themselves: Why do you imagine all the major religions believe in a life after this one, and why have hundreds of millions of people throughout history, including the greatest philosophers, sages, and creative geniuses of Asia, lived this belief as an essential part of their lives? Were they all simply deluded?
(Sogyal Rinpoche)